The present invention relates to a combination lock that is portable for locking luggage, lockers, doors and the like.
Padlocks are widely used in various occasions to provide safety protection for goods and properties. At present there are many different types of padlocks available on the market. Their functions also arc enhanced and improved constantly.
Conventional padlocks can be classified in two types: padlocks with keys and combination locks. The former type requires mating keys to do unlocking and the later type has a mechanism to set unlocking password. While both types have their unique functions, to people who care about losing keys, the combination lock is a preferred choice.
Refer to FIG. 1 for a conventional combination lock. It has a plurality of visible number disks located in the lock housing. Each number disk has a set number (or character or pattern) to combine with other set numbers to form an unlocking number set. The lock can be unlocked only after all of the number disks have been turned and aligned to the preset numbers.
The design of multiple number disks has become one of the standards of the combination locks. However, the prolific choices of the dialing and unlocking mechanism increase the costs of materials, production and management. In addition, the exposed dialing disks also become a limitation of the exterior design.
In view of the aforesaid disadvantages, the primary object of the invention is to provide a lock that has a simpler structure and is easier to use.
In order to achieve the foregoing object, the invention provides an improved combination lock that employs only one dial to set the password with two or more numerals. The combination lock according to the invention includes a lock housing, a shackle, a lock shaft, an elastic element, a dial and a plurality of retaining rings. The dial is the only control element to perform the locking or unlocking function. It forms rotational chain movements with the retaining rings such that the retaining rings may generate a constraint or a release movement on the lock shaft to determine indirectly whether the shackle may be moved relative to the lock housing from a locked position to an unlocked position.
When in use, the dial and the retaining ring are engaged respectively with a turning wheel and a turning ring, and are coupled on a sleeve mounted onto the lock shaft. Moreover, the sleeve has one side connecting to an number alteration bolt. When the number alteration bolt is subjected to a force, it drives the sleeve to escape the turning ring so that the turning ring may change position and then couple with the sleeve again to achieve the function of password alteration.
The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.
Further scope of the applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.